Hi Mike,
I have not followed this thread, so am guessing a bit here . The
cybersync units are rated to trigger up to 300V , so almost definitely use an
SCR switch. The scr drops about 1.2V when triggered, so severly limits the
voltage from a 3V battery when triggering a flash bulb. . The Cybersync
units are rated to trigger either positive or negative polarity. This likely
requires an additional diode which drops another 0.7V or 1.9V total. So not
surprising they cannot fire a 3V powered flash device.
At 3V the flash bulb likely takes a lot longer to fire. This is because the
current must heat up the magnesium wire to ignition point. The heat is
supplied at a rate proportional to Volts squared. So all else being equal the
difference in heating rate (delay) between 22V and 3V is ~40+ times! In
reality the current available is limited by both the voltage and the internal
resistance of the battery/capacitor combination. That is why a capacitor in
good working order is important in the flash unit. An old dried out capacitor
cannot provide high current.
If you send me a picture of the old capacitor with measured dimensions, I may
be able to help you find a replacement. There are some very small rechargeable
Li batteries that are now capable of high current, which might work well here,
even without a capacitor as they can deliver more than 1A. Contact me off list
for more info.
It depends on how they drive the SCR, but in general once triggered the scr
continues conducting until the current drops off to a small value. So it is
fairly likely their is no trigger duration limitation here.
In OM2N's there is a series diode (1N4004) to isolate the pc connector from
the hot shoe. This drops 0.7V if using the pc sync connector. The OM2s uses an
scr, so drops even more.
Tim Hughes
--- On Tue, 4/26/11, usher99@xxxxxxx <usher99@xxxxxxx> wrote:
From: usher99@xxxxxxx <usher99@xxxxxxx>
Subject: [OM] Can Cybersync battery receivers/transmitters trigger a large
flash bulb?
To: olympus@xxxxxxxxxxxxxxxxx
Cc: timhughes@xxxxxxxx
Date: Tuesday, April 26, 2011, 5:01 PM
Hi Chuck,
Thanks for asking about the Cybersyncs. Yep, still plenty of flashbulbs
of various flavors yet to go. I found
the "mother load" at my mother's of course. Most numerous are the GE
6B's. I would be happy to sacrifice one in the name of science.
I did like your analogy of lighting a candle in triggering the FB.
>From my digging around about this, the older cheapo FB brackets just
used 3V or so to start the burn--less reliable and I suspect requires a
more prolonged current to ignite.
Now I sprung a bit more dosh for a replacement 22.5 V
battery in lieu of the two D cell solution and it has a cap at the end
battery module for the FB bracket. I searched around for new caps, but
I couldn't find
any, though I am no expert at finding oddball caps.
I tried a few bulbs to see if it fired reliably with the PC socket
before (on the 2N but not the OM2 I was using) and it seemed fine
even with another auxiliary FB hooked up in a floor lamp. I wouldn't
think a very long pulse with the cap in the circuit would
be necessary--perhaps it is leaky. I kinda -sorta remember though that
the cheapo yabe radiotriggers would not even fire some
electronic flashes, but perhaps I am misremembering an old post. I must
say I was very surprised and disappointed the FB didn't fire with the
radiotrigger in the hotshoe. Perhaps I should have tested the cap
specifically and not just assessing if the FB would fire.
I bet Tim would have a handle on this. I'll cc him this directly.
Haven't heard form him for awhile. Hope all is well.
I too am enamored of the FP option and had visions of macro fill flash
at any
speed using various size FP FB's radio triggered
with various diffusers. A more flexible and more powerful F280, No? So
far mostly a thought experiment . I am still curious if TTL auto mode
will meter the FB's properly in FP mode. Now Xsync will still work with
the FP FB's , but one must drag the shutter quite a bit for it to work
well
--not as elegant.
Still in the Dark, Mike
I sent the following reply to Paul Buff, Inc. after receiving a "we
don't know
about FP timing" reply from their tech support. Got any bulbs left,
Mike?
Maybe I can loan you my CyberSyncs sometime after I get home Wednesday
night.
I'm interested to know the outcome.
Chuck Norcutt
> -------Original Message-------
> From: chucknorcutt [at] chucknorcutt.com
> To: Info at Paulcbuff.com <info [at] paulcbuff.com>
> Subject: RE: Can Cybersync battery receivers/transmitters trigger a
large
> flash bulb?
> Sent: Apr 26 '11 11:24
>
> Thanks for the reply, David.ÂÂMy guess is that you're much younger
than my
> 67 years since you appear to have little knowledge of FP (focal
plane) flash
> bulbs.ÂÂThe camera I mentioned (an Olympus OM-2) is a mid-70s film
SLR and
> the last of the OM line of cameras to support FP synchronization
(focal plane
> flash bulbs) as well as X sync for electronic flash.ÂÂSelection of
the sync
> speed is via a two position switch near the lens mount.
>
> You are correct about the timing for FP bulbs.ÂÂUnlike electronic
flash
> (which can only be fired at shutter speeds slow enough that both
curtains of
> a focal plane shutter are fully open), FP bulbs are
specificallyÂÂdesigned
> for use with focal plane shutters and can be used at any shutter
speed.ÂÂThey
> have a very long burn time which, to assure compete coverage of the
image
> plane, must be at least as long as the X-sync time for the camera.
For the
> OM-2 that's at least 1/60 second and I suspect large FP bulbs may
have burn
> times of 1/30 second or longer for the even larger and
slower-shuttered
> medium format SLRs of the day. In addition to the long burn time
there is
> also an extended ignition time.ÂÂThat simply means that it takes the
bulb
> some appreciable time to start burning at a constant rate which is
necessary
> for even illumination as the slit formed by the focal plane shutter
traverses
> the image plane. So, you are also correct thatÂÂthe timing for FP
sync trig
gers the bulb well before the shutter starts to open.ÂÂI appreciate
the
information on the 1/4000th latency of the CyberSync.ÂÂI don't have
precise
knowledge of how that will affect an FP bulb but suspect that something
that
fast is in the range of random noise for something with the long ramp
up time
of an FP bulb.
>
> What I had hoped you might be able to supply me with was the amount
of time
> that the CyberSync trigger signal is actually being transmitted. Our
concern
> is that it might not be long enough to assure reliable
ignition.ÂÂIt's sort
> of like trying to light a candle with a match.ÂÂIf you place the lit
match in
> contact with the candle wick for 1/10 second you're not likely to
light the
> candle. Any signal duration timing info you have will be appreciated.
>
> It's possible I may simply lend my CyberSyncs (by mail) to the
friend with
> the FP bulbs.ÂÂIf I do I'll advise you of the outcome of the
experiment.
>
> Chuck Norcutt
>
>
> >ÂÂ-------Original Message-------
> >ÂÂFrom: Info at Paulcbuff.com <info [at] paulcbuff.com>
> >ÂÂTo: chucknorcutt [at] chucknorcutt.com
> >ÂÂSubject: RE: Can Cybersync battery receivers/transmitters trigger
a large
> flash bulb?
> >ÂÂSent: Apr 26 '11 10:24
> >ÂÂ
> >ÂÂHey Chuck,
> >ÂÂThanks for contacting us! Unfortunately, this has not been tested
by us,
> and
> >ÂÂI am not familiar enough with those type bulbs to make an
educated guess.
> I
> >ÂÂwould think if they can be triggered by jumping a sync cord, they
can
> likely
> >ÂÂbe triggered by a CSRB with the correct wiring. However, some
additional
> >ÂÂthoughts on this: Are you using this with a typical DSLR, or do
you have a
> >ÂÂcamera designed to use these, and you just are looking for a
wireless
> >ÂÂsolution? My research has lead to my understanding that these
need a sync
> >ÂÂconnection that will trigger in advance of the shutter opening. A
standard
> >ÂÂsync connection will not do that, and cause the lights to trigger
too
> late.
> >ÂÂAdditionally, regardless of the camera, the all radio remotes
introduce
> some
> >ÂÂlatency. In the case of Cyber Sync, it is about 1/4000, which may
or may
> not
> >ÂÂskew the timing of the trigger.
> >ÂÂ
> >ÂÂI hope this helps, and if there is anything else we can do to
assist,
> please
> >ÂÂlet us know!
> >ÂÂ
> >ÂÂThanks again,
> >ÂÂDavid
> >ÂÂPaul C. Buff, Inc.
> >ÂÂ1-800-443-5542
> >ÂÂ
> >ÂÂ-----Original Message-----
> >ÂÂFrom: chucknorcutt [at] chucknorcutt.com [mailto:chucknorcutt
[at]
> chucknorcutt.com]
> >ÂÂSent: Saturday, April 23, 2011 9:25 AM
> >ÂÂTo: tech [at] paulcbuff.com
> >ÂÂSubject: Can Cybersync battery receivers/transmitters trigger a
large
> flash
> >ÂÂbulb?
> >ÂÂ
> >ÂÂA friend has acquired a large flash gun and a supply of FP
bulbs.ÂÂ
> Assuming
> >ÂÂthat a Cybersync transmitter is attached to a camera with FP sync
(an
> >ÂÂOlympus Om-2) will the receiver trigger the bulb? Another friend
has
> >ÂÂspeculated that radio triggers designed for electronic flash may
not have
> >ÂÂsufficient duration to trigger the bulb.ÂÂAdvice?
> >ÂÂ
> >ÂÂChuck Norcutt
> >ÂÂEndwell, NY
> >ÂÂ
> >ÂÂ
>
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